JPS6388271A - Throttle body for fuel injection device - Google Patents

Abstract

PURPOSE:To achieve the simplification of a fuel passage structure by connecting each other a main and an auxiliary injection valve, fitted in the positions on the upstream side and downstream side of a throttle body proper so as to face the intake air passage, by fuel passages inside the body proper. CONSTITUTION:On the body proper 2 of a throttle body 1, a main injection valve 12 is fitted in the upstream side position, and an auxiliary injection valve 13 in the downstream side position, each of which is arranged so as to face the intake air passage, and respective injection passages 8, 9 are connected by fuel passages 18-20 provided inside the body 2. And, high-pressure fuel introduced from a pipe line 15 is passed through a passage 17, and injection passage 9, passages 18-20, an injection passage 8, and a passage 24 to control the pressure by a pressure control valve 29 in response to the negative pressure from a pipe 28, and relief fuel is returned to a fuel tank through an outlet pipe line. Thus, the structure of fuel passages can be simplified, and the degree of freedom in the layout inside an engine room can be enhanced.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to a throttle body for a fuel injection device used in an internal combustion engine, and in particular to a main injection valve improved to have a simplified fuel passage structure. and a sub-injector.

<Prior Art> Fuel injection systems for internal combustion engines have conventionally used an injection method (multi-point injection) in which an injection valve is individually provided for each intake port and fuel is injected into the intake stroke of each cylinder. ) is known, but because it requires an injection valve for each cylinder, it is relatively expensive and rare.

Therefore, in recent years, there has been a tendency to adopt a throttle body injection method (single point injection) in which an injector is provided in a throttle body provided in an intake passage, similar to a carburetor.

According to this method, the number of components is small, and the fuel can be expected to vaporize in the intake passage. In particular, in a type of throttle body that has an air valve and a throttle valve arranged on the upstream and downstream sides of the intake passage, the air valve restricts the intake flow to a certain extent even when the engine is running at low speed. As a result, fuel can be injected into the intake air flow having a relatively high flow velocity, and the fuel can be atomized over a wide operating range.

However, in reality, fuel injection! In order to perform accurate metering in the small iFIm range and to inject a sufficient amount of fuel at high loads and high speeds, in other words, to widen the dynamic range of fuel injection, the main injector and It is desirable to use it together with a sub-injection valve. Therefore, relatively low pressure fuel is supplied to such a fuel injection valve, but a pressure control valve is provided near the fuel injection valve,
Moreover, since it is necessary to provide a fuel passage for each of the main and auxiliary injectors, the configuration of the pipeline as a fuel passage tends to become complicated, and it is difficult to ensure the reliability of the pipeline and avoid interference with other equipment. This requires a great deal of effort and cost.

Japanese Unexamined Patent Publication No. 56-8265 discloses a structure in which a fuel 1:31 passage is provided inside a beam-shaped body that supports a fuel injection valve, but this structure connects the fuel injection valve to the intake passage of the throttle body. Applicable only when held concentrically.

<Problems to be Solved by the Invention> In response to these drawbacks of the prior art, the main object of the present invention is to provide a fuel injection valve that is equipped with a main injection valve and a sub-injection valve, and has a simplified fuel passage structure. An object of the present invention is to provide a throttle body for a fuel injection device.

<Means for Solving the Problems> According to the present invention, the present invention has an injection valve that injects fuel into an intake passage installed in a small body, and an injection valve located downstream of the intake passage. In the throttle body for a fuel injection device, the throttle body has a throttle valve provided therein, and an air valve provided in the intake path upstream of the throttle valve to open and close the intake path according to intake negative pressure. The injection valve has a main injection valve and a sub-injection valve attached to an upstream position and a downstream position of the body body facing the intake passage, and the fuel injection valve is installed inside the body body. This is achieved by providing a throttle body for a fuel injection fJJ device, characterized in that both the injection valves are connected to each other by a passage.

<Function> In this way, if both the main and sub-injectors are communicated with each other through the fuel passages built into the main body, for example, by integrally mounting the pressure control valve on the main injector, the fuel supply pipe can be connected. This eliminates the need for any pipe line other than the fuel return pipe line, making it possible to simplify the fuel passage structure to the utmost.

<Embodiments> Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIGS. 1 and 2, a throttle body 1 according to the present invention has an intake passage 3 disposed inside a body main body 2. As shown in FIGS. On the upstream side of the intake path communicating with an air cleaner (not shown), an air valve 5 is rotatably supported by a valve shaft 4 at an offset position, and is connected to an intake manifold (not shown). A throttle valve 7 is rotatably supported by a valve shaft 6 on the downstream side of the intake passage.

A torsion coil spring, a negative pressure actuator, etc. (not shown) are connected to the outer end of the valve shaft 4 of the air valve 5, and the air valve 5 is controlled to open or close depending on the magnitude of negative pressure on the downstream side of the air valve 5, for example. . Further, a torsion coil spring, a throttle lever, etc. (not shown) are attached to the outer end of the valve shaft 6 of the throttle valve 7, and the opening and closing of the throttle valve 7 is controlled by a throttle pedal or the like in a manner known per se.

A pair of injection passages 8.9 that open obliquely toward the downstream side of the intake passage 3 are provided on one side of the body main body 2, and inside these injection passages 8.9, a main injection valve 12 and a sub-injection valve 12 are installed. A valve 13 is installed. The outer openings of these injection channels 8.9 are also closed by caps 10.11.

The frontage of the injection passage 8 of the main injection valve 12 on the side of the intake passage 3 is
It is opened at a position facing the edge of the air valve 5, and the end of the injection passage 9 of the sub-injection valve 13 on the intake path 3 side is opened slightly downstream of the throttle valve 7. A notch 5a is provided in a portion of the air valve 5 adjacent to the injection passage 8 of the main injection valve 12 to avoid interference between the fuel injected from the injection passage 8 and the air valve 5. Furthermore, both these injection valves 12.1
A bypass air passage 14 that bypasses the throttle valve 7 is provided inside the body main body 2 on the side opposite to the throttle valve 3 .

Next, with particular reference to FIG.
The fuel passage No. 3 will be explained.

The fuel supply pipe 15 is connected to a joint 1 screwed into the body main body 2.
6 and a sub-injection valve 13 laterally bored in the body main body 2.
It communicates with the sub-injection valve 13 via a fuel passage 17 that leads to a fuel injection passage 9 . Further, a fuel passage 18 is formed laterally at a diagonal position with respect to the fuel passage 17, a fuel passage 20 is formed laterally towards the fuel injection passage 8 of the main injection valve 12, and a fuel passage 20 is formed laterally at a diagonal position with respect to the fuel passage 17. The auxiliary injection valve 1 is connected to the auxiliary injection valve 1 by a communication passage consisting of one fuel passage perforated in the main body 2 in a substantially vertical direction so as to communicate the directional fuel passages 18 and 20 with each other.
A fuel passage from the main injection valve 3 to the main injection valve 12 is formed.

Incidentally, these fuel passages 17 to 20 may be formed by drilling and may be appropriately closed by ball plugs 21 to 23 as necessary.

Furthermore, a fuel passage 24 that is laterally bored at a diagonal position with respect to the lateral passage 20 of the main injection valve 12 is connected to the main body 2.
It opens at a flange surface 25 provided on the outer surface of the
A pressure control valve 29 is screwed onto the flange surface 25 by bolts (not shown) such that its inlet opening 26 and fuel passage 24 are aligned. The outlet pipes 27 of these two pressure control valves form a return passage leading to the fuel tank.
The relief pressure of the pressure control valve 29 is controlled by the negative pressure supplied from the negative pressure line 28 to these two pressure control valves, and the required fuel pressure of both the main and sub injection valves 12 and 13 is ensured.

<Effects of the Invention> As described above, according to the present invention, although both main and sub-injectors are provided in the throttle body main body, the structure of the fuel passage is simplified, and the layout within the engine room is simplified. Not only does the degree of freedom increase, but the pipe line and its joint can be omitted, and the reliability of the fuel passage can be easily ensured. Furthermore, by simplifying the conduit, the number of manufacturing steps can be reduced. Furthermore, by making the direction of fuel flow in these fuel passages upward from the sub-injection valve to the main injection valve, there is less risk that air mixed in the fuel will remain in the fuel passage. It is possible to avoid disturbances in the injection matrix due to air intrusion.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view of an embodiment of a throttle body for a fuel injection device according to the present invention. FIG. 2 is a front view of the throttle body of FIG. 1, showing the throttle body main body with imaginary lines and clearly showing the configuration of the fuel passage. 1... Throttle body 2... Body main body 3...
Intake path 4... Valve stem 5... Air valve
5a... Notch 6... Valve stem 7...
Throttle valve 8.9... Injection passage 10.11...
・Cap 12.13...Injection valve 14...Bypass air passage 15...Pipe line 16...Joint 1
7-20... Passage 21-23... Ball plug 24... Passage 25... Flange surface 26.
...Inlet opening 27...Outlet pipe line 28...Negative pressure pipe line 29...Pressure control valve patent applicant
Honda Motor Co., Ltd. Representative Patent Attorney Yo Oshima - Figure 1 Figure 2

Claims (2)

[Claims] (1) An injection valve that injects and supplies fuel into an intake passage installed inside the body, a throttle valve installed at a downstream position of the intake passage, and an injector that opens and closes the intake passage according to intake negative pressure. In a throttle body for a fuel injection device having an air valve provided in an intake passage upstream of the throttle valve, the injection valve has an upstream position facing the intake passage of the body main body and a downstream position facing the intake passage. A fuel injection system comprising a main injection valve and a sub-injection valve respectively attached to the body, and both the injection valves are connected to each other by a communication fuel passage provided inside the body main body. Throttle body for equipment. (2) The throttle body for a fuel injection device according to claim 1, wherein the communication fuel passage extends downward on the road.